def getUDPPacket(self):
"""
构造UDP数据包
:param self:
:return:
"""
try:
ip_packet = IP()
ip_packet.version = int(self.entries[3].get())
ip_packet.ihl = int(self.entries[4].get())
ip_packet.tos = int(self.entries[5].get())
ip_packet.id = int(self.entries[6].get())
# ip_packet.flags = int(self.entries[7].get())
ip_packet.frag = int(self.entries[8].get())
ip_packet.ttl = int(self.entries[9].get())
# ip_packet.chksum = self.entries[10].get()
ip_packet.src = self.entries[11].get()
ip_packet.dst = self.entries[12].get()
udp_packet = UDP()
udp_packet.sport = int(self.entries[0].get())
udp_packet.dport = int(self.entries[1].get())
# udp_packet.chksum = int(self.entries[2].get())
# scapy自动计算IP、UDP校验和
# 获得数据包的二进制值
pkg_raw = raw(ip_packet / udp_packet)
udp_packet_raw = pkg_raw[20:]
# 构造数据包，自动计算校验和
scapy_chksum_IP = IP(pkg_raw).chksum
scapy_chksum_udp = UDP(udp_packet_raw).chksum
print("scapy自动计算的UDP校验和为：%04x" % scapy_chksum_udp)
# 手动计算UDP校验和
udp_packet.chksum = 0
packet = ip_packet / udp_packet
udp_raw = raw(packet)[20:]
self_chksum = in4_chksum(socket.IPPROTO_UDP, packet[IP], udp_raw)
print("手动计算的UDP校验和为：%04x" % self_chksum)
if self_chksum == scapy_chksum_udp:
print("UDP验证和正确")
else:
print("UDP验证和不正确")
udp_packet.chksum = scapy_chksum_udp
self.entries[2].delete(0, END)
self.entries[2].insert(0, hex(scapy_chksum_udp))
self.entries[10].delete(0, END)
self.entries[10].insert(0, hex(scapy_chksum_IP))
udp_packet.show()
self.resultText.insert('end', udp_packet.summary() + '\n')
self.resultText.insert('end', str(udp_packet) + '\n')
return Ether() / ip_packet / udp_packet
except Exception as e:
print(e.with_traceback())
finally:
pass
def post_dissect(self, data):
# uncompress payload
packet = IPv6()
packet.version = IPHC_DEFAULT_VERSION
packet.tc = self.traffic_class
packet.fl = self.flow_label
nh_match = {
1: socket.IPPROTO_UDP,
2: socket.IPPROTO_ICMP,
3: socket.IPPROTO_TCP
}
if self.nh:
packet.nh = nh_match.get(self.nh)
packet.hlim = self.hopLimit
packet.src = self.decompressSourceAddr()
packet.dst = self.decompressDestAddr()
if self.hc2 and self.nh == 1: # UDP
udp = UDP()
udp.sport = self.udpSourcePort
udp.dport = self.udpDestPort
udp.len = self.udpLength or None
udp.chksum = self.udpChecksum
udp.add_payload(data)
packet.add_payload(udp)
else:
packet.add_payload(data)
data = raw(packet)
return Packet.post_dissect(self, data)
def post_dissect(self, data):
if not self.underlayer or not hasattr(self.underlayer, "_ipv6"):
return data
if self.guess_payload_class(data) != IPv6:
return data
# Underlayer is LoWPAN_IPHC
packet = self.underlayer._ipv6
try:
ipv6_hdr = next(
x for x in self.exts if isinstance(x, LoWPAN_NHC_IPv6Ext)
)
except StopIteration:
ipv6_hdr = None
if ipv6_hdr:
# XXX todo: implement: append the IPv6 extension
# packet = packet / ipv6extension
pass
try:
udp_hdr = next(
x for x in self.exts if isinstance(x, LoWPAN_NHC_UDP)
)
except StopIteration:
udp_hdr = None
if udp_hdr:
packet.nh = 0x11 # UDP
udp = UDP()
# https://tools.ietf.org/html/rfc6282#section-4.3.3
if udp_hdr.C == 0:
udp.chksum = udp_hdr.udpChecksum
if udp_hdr.P == 0:
udp.sport = udp_hdr.udpSourcePort
udp.dport = udp_hdr.udpDestPort
elif udp_hdr.P == 1:
udp.sport = udp_hdr.udpSourcePort
udp.dport = 0xF000 + udp_hdr.udpDestPort
elif udp_hdr.P == 2:
udp.sport = 0xF000 + udp_hdr.udpSourcePort
udp.dport = udp_hdr.udpDestPort
elif udp_hdr.P == 3:
udp.sport = 0xF0B0 + udp_hdr.udpSourcePort
udp.dport = 0xF0B0 + udp_hdr.udpDestPort
packet.lastlayer().add_payload(udp / data)
else:
packet.lastlayer().add_payload(data)
data = raw(packet)
return Packet.post_dissect(self, data)
def post_dissect(self, data):
"""dissect the IPv6 package compressed into this IPHC packet.
The packet payload needs to be decompressed and depending on the
arguments, several conversions should be done.
"""
# uncompress payload
packet = IPv6()
packet.version = IPHC_DEFAULT_VERSION
packet.tc, packet.fl = self._getTrafficClassAndFlowLabel()
if not self.nh:
packet.nh = self._nhField
# HLIM: Hop Limit
if self.hlim == 0:
packet.hlim = self._hopLimit
elif self.hlim == 0x1:
packet.hlim = 1
elif self.hlim == 0x2:
packet.hlim = 64
else:
packet.hlim = 255
# TODO: Payload length can be inferred from lower layers from either the # noqa: E501
# 6LoWPAN Fragmentation header or the IEEE802.15.4 header
packet.src = self.decompressSourceAddr(packet)
packet.dst = self.decompressDestinyAddr(packet)
if self.nh == 1:
# The Next Header field is compressed and the next header is
# encoded using LOWPAN_NHC
udp = UDP()
if self.header_compression and \
self.header_compression & 0x4 == 0x0:
udp.chksum = self.udpChecksum
s, d = nhc_port(self)
if s == 16:
udp.sport = self.udpSourcePort
elif s == 8:
udp.sport = 0xF000 + s
elif s == 4:
udp.sport = 0xF0B0 + s
if d == 16:
udp.dport = self.udpDestinyPort
elif d == 8:
udp.dport = 0xF000 + d
elif d == 4:
udp.dport = 0xF0B0 + d
packet.payload = udp / data
data = raw(packet)
# else self.nh == 0 not necessary
elif self._nhField & 0xE0 == 0xE0: # IPv6 Extension Header Decompression # noqa: E501
warning('Unimplemented: IPv6 Extension Header decompression'
) # noqa: E501
packet.payload = conf.raw_layer(data)
data = raw(packet)
else:
packet.payload = conf.raw_layer(data)
data = raw(packet)
return Packet.post_dissect(self, data)
def post_dissect(self, data):
"""dissect the IPv6 package compressed into this IPHC packet.
The packet payload needs to be decompressed and depending on the
arguments, several conversions should be done.
"""
# uncompress payload
packet = IPv6()
packet.version = IPHC_DEFAULT_VERSION
packet.tc, packet.fl = self._getTrafficClassAndFlowLabel()
if not self.nh:
packet.nh = self._nhField
# HLIM: Hop Limit
if self.hlim == 0:
packet.hlim = self._hopLimit
elif self.hlim == 0x1:
packet.hlim = 1
elif self.hlim == 0x2:
packet.hlim = 64
else:
packet.hlim = 255
# TODO: Payload length can be inferred from lower layers from either the # noqa: E501
# 6LoWPAN Fragmentation header or the IEEE802.15.4 header
packet.src = self.decompressSourceAddr(packet)
packet.dst = self.decompressDestinyAddr(packet)
if self.nh == 1:
# The Next Header field is compressed and the next header is
# encoded using LOWPAN_NHC
udp = UDP()
if self.header_compression and \
self.header_compression & 0x4 == 0x0:
udp.chksum = self.udpChecksum
s, d = nhc_port(self)
if s == 16:
udp.sport = self.udpSourcePort
elif s == 8:
udp.sport = 0xF000 + s
elif s == 4:
udp.sport = 0xF0B0 + s
if d == 16:
udp.dport = self.udpDestinyPort
elif d == 8:
udp.dport = 0xF000 + d
elif d == 4:
udp.dport = 0xF0B0 + d
packet.payload = udp / data
data = raw(packet)
# else self.nh == 0 not necessary
elif self._nhField & 0xE0 == 0xE0: # IPv6 Extension Header Decompression # noqa: E501
warning('Unimplemented: IPv6 Extension Header decompression') # noqa: E501
packet.payload = conf.raw_layer(data)
data = raw(packet)
else:
packet.payload = conf.raw_layer(data)
data = raw(packet)
return Packet.post_dissect(self, data)
